Convert number grade to letter. Write a program that prompts the user to enter a numeric grade 4, 3, 2, 1, or 0 and displays its corresponding letter value A, B, C, D, or F. Here is a sample run (user input in color): Enter a numeric grade: 3 The letter value for grade 3 is B

4. what is the reason for including the following code snippet in the header file animal.h? #ifndef animal_h #define animal_h class animal { public: animal(); animal(double new_area_hunt); void birth(); void hunt(double new_area_hunt); void death(); double get_area_hunt() const; private: double area_hunt; }; #endif